Conventional powder coating processes involve spraying a coating of polymer plastic powder onto an object, and then applying heat to the coating. The heat applied must be sufficient to cure the powder and, if applicable, to enable it to chemically react, but not so extreme in either time or duration as to cause the polymer to start to decompose. When heat is removed, the powder hardens onto the object.
In theory, powder coating will work effectively with any object that can withstand the application of the heat necessary to melt the powder. In practice, however, problems are often encountered in getting the powder to adhere to the object. In an effort to improve adherence of powder, the object being coated is commonly heated or electrostatically charged.
A particularly difficult material to get a polymer plastic powder to adhere to is wood. Notwithstanding the heating of the wood and the use of electrostatic application methods, the quality of powder coating finishes on wood have generally been unsatisfactory.